Without enough saliva you can develop tooth decay or other infections in the
mouth. You also might not get the nutrients you need if you cannot chew and
swallow certain foods.

What causes dry mouth?

People get dry mouth when the glands in the mouth that make saliva are not
working properly. Because of this, there might not be enough saliva to keep your
mouth wet. There are several reasons why these glands (called salivary glands)
might not work right.

Side effects of some medicines. More than 400 medicines can cause the
salivary glands to make less saliva. For example, medicines for high blood pressure and depression often cause dry mouth.